<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - trails</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				background:#000;
				padding:0;
				margin:0;
				font-weight: bold;
				overflow:hidden;
			}
		</style>
	</head>
	<body>

		<script src="../build/three.js"></script>

		<script src="js/libs/stats.min.js"></script>

		<script>

			var container, stats;

			var camera, scene, renderer;

			var mouseX = 0, mouseY = 0;

			var windowHalfX = window.innerWidth / 2;
			var windowHalfY = window.innerHeight / 2;

			init();
			animate();

			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.set( 100000, 0, 3200 );

				scene = new THREE.Scene();

				var colors = [ 0x000000, 0xff0080, 0x8000ff, 0xffffff ];
				var geometry = new THREE.Geometry();

				for ( var i = 0; i < 2000; i ++ ) {

					var vertex = new THREE.Vector3();
					vertex.x = Math.random() * 4000 - 2000;
					vertex.y = Math.random() * 4000 - 2000;
					vertex.z = Math.random() * 4000 - 2000;
					geometry.vertices.push( vertex );

					geometry.colors.push( new THREE.Color( colors[ Math.floor( Math.random() * colors.length ) ] ) );

				}

				var material = new THREE.PointsMaterial( { size: 1, vertexColors: THREE. VertexColors, depthTest: false, opacity: 0.5, sizeAttenuation: false, transparent: true } );

				var mesh = new THREE.Points( geometry, material );
				scene.add( mesh );

				renderer = new THREE.WebGLRenderer( { preserveDrawingBuffer: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.sortObjects = false;
				renderer.autoClearColor = false;
				container.appendChild( renderer.domElement );

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				document.addEventListener( 'mousemove', onDocumentMouseMove, false );

				window.addEventListener( 'resize', onWindowResize, false );

			}

			function onWindowResize() {

				windowHalfX = window.innerWidth / 2;
				windowHalfY = window.innerHeight / 2;

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function onDocumentMouseMove(event) {

				mouseX = ( event.clientX - windowHalfX ) * 10;
				mouseY = ( event.clientY - windowHalfY ) * 10;

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				camera.position.x += ( mouseX - camera.position.x ) * .05;
				camera.position.y += ( - mouseY - camera.position.y ) * .05;

				camera.lookAt( scene.position );

				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>
